The ability to obtain different wines with a singular organoleptic profile is one of the main factors for the wine industry’s growth, in order to appeal to a broad cross section of consumers. Due to this, white wines made from the novel grape genotypes Albillo Dorado and Montonera del Casar (Vitis vinifera L.) were studied and compared to the well-known Airén at two consecutive years. Wines were evaluated by physicochemical, spectrophotometric, high-performance liquid chromatography–diode array detection–mass spectrometry, gas chromatography–mass spectrometry and sensory analyses. The chromatic characteristics of the new wines were defined by more color purity than Airén, with greenish highlights. In general, the phenolic profile of the Albillo Dorado wines showed a higher flavonol and hydroxycinnamic acid derivative content. Several volatile compounds were determined, and their odor activity values were calculated to determine their impact on wine aroma. A fruity series dominated the wine aromatic composition, but spicier and greener notes characterized the aroma profile of Airén wines. Albillo Dorado and Montonera del Casar were sensory evaluated as wines with a less fresh taste compared to Airén. Unique chemical and sensory profiles were determined for wines made from these novel grape genotypes, providing alternative monovarietal wines to encourage the wine market growth and extend the offer to consumers.
Climate change is affecting vineyards, resulting in grapes with a low acidity a high pH and sugar at harvest time. The most common procedure so far to improve the acidity and reduce the final pH of wines is to use tartaric acid, but wine can also be acidified microbiologically using Lachancea thermotolerans yeasts, a natural bio-tool that acidifies gradually during the first stage/days of fermentation. Two strains of L. thermotolerans were compared with one Saccharomyces cerevisiae at a pilot-scale under similar fermentation conditions and in duplicate. A sequential inoculation was performed on the third day for the non-Saccharomyces, producing only about 1 g/L of lactic acid, which was suitable for comparison with the Saccharomyces, to which 1.5 g/L of tartaric acid had been added to lower the final pH. The three fermentations ended with a total acidity without significant differences. A significant and normal feature of the L. thermotolerans yeasts is their higher propane-1,2,3-triol production, which was observed in the Laktia yeast, and the acetic acid was <0.3 g/L. The amount of volatile metabolites was generally higher for non-Saccharomyces and the increase was seen in carbonyl compounds, organic acids, lactones, fumaric compounds, and phenols. Finally, the sensory analysis showed that there were hardly any significant differences, even though the non-Saccharomyces had a higher quantity of volatile metabolites, which could lead to a good acceptance of the product, since biological acidification was used, generating a more natural product.
This study investigates the effects of simultaneous inoculation of a selected Saccharomyces cerevisiae yeast strain with two different commercial strains of wine bacteria Oenococcus oeni at the beginning of the alcoholic fermentation on the kinetics of malolactic fermentation (MLF), wine chemical composition, and organoleptic characteristics in comparison with spontaneous MLF in Tempranillo grape must from Castilla-La Mancha (Spain). Evolution of MLF was assessed by the periodic analysis of L-malic acid through the enzymatic method, and most common physiochemical parameters and sensory traits were evaluated using a standardized sensory analysis. The samples were analyzed by GC/MS in SCAN mode using a Trace GC gas chromatograph and a DSQII quadrupole mass analyzer. Co-inoculation reduced the overall fermentation time by up to 2 weeks leading to a lower increase in volatile acidity. The fermentation-derived wine volatiles profile was distinct between the co-inoculated wines and spontaneous MLF and was influenced by the selected wine bacteria used in co-inoculation. Co-inoculation allows MLF to develop under reductive conditions and results in wines with very few lactic and buttery flavors, which is related to the impact of specific compounds like 2,3-butanedione. This compound has been also confirmed as being dependent on the wine bacteria used.
Drought is perhaps the most important abiotic stressor affecting plants. Grapevine (Vitis vinifera L.) is a drought-tolerant species, and this feature makes it a traditional crop in semi-arid climate areas. However, not all cultivars respond to drought in the same way. Many studies on grapevine drought response have focused on physiological traits. This study mainly used agronomic indicators to assess the drought response of 13 red cultivars. Our results revealed high variability in must isotope ratios (δ13C and δ18O), yield components, and grape must quality. Bobal, Garnacha Peluda, Garnacha Tinta, Mazuela, and Moribel cultivars responded well to drought conditions, simultaneously maintaining high yields and must quality. By contrast, Garnacha Tintorera, Forcallat Tinta, and Tempranillo cultivars showed high water use efficiency but had low yield and must quality. Therefore, these cultivars can be considered poorly adapted to drought conditions. By knowing which cultivars perform well under drought conditions, viticulturists can reduce their reliance on water irrigation and continue to maintain vineyard sustainability in current and future semi-arid climatic conditions. This research also contributes novel information about the Castilla-La Mancha region, where there have been no previous similar assays.
13 November 2024 in International Journal of Food Microbiology
Summary: Pistachio is a sustainable nut crop with exceptional climate resilience and nutritional value. However, the molecular processes underlying pistachio nut development and nutritional traits are largely unknown, compounded by limited genomic and molecular resources. To advance pistachios as a future food source and a model system for hard‐shelled fruits, we generated a chromosome‐scale reference genome of the most widely grown pistachio cultivar (Pistacia vera ‘Kerman’) and a spatiotemporal study of nut development. We integrated tissue‐level physiological data from thousands of nuts over three growing seasons with transcriptomic data encompassing 14 developmental time points of the hull, shell, and kernel to assemble gene modules associated with physiological changes. Our study defined four distinct stages of pistachio nut growth and maturation. We then focused on the kernel to identify transcriptional and metabolic changes in molecular pathways governing nutritional quality, such as the accumulation of unsaturated fatty acids, which are vital for shelf life and dietary value. These findings revealed key candidate conserved regulatory genes, such as PvAP2‐WRI1 and PvNFYB‐LEC1, likely involved in oil accumulation in kernels. This work yields new knowledge and resources that will inform other woody crops and facilitate further improvement of pistachio as a globally significant, sustainable, and nutritious crop.